Installation of platform screen doors on platforms at stations of a railway and the like has been promoted in order to prevent accidents of falling from platforms, accidents of contacting with a train and the like. Various types of platform doors have been known; the doors include a full-screen type platform screen door that isolates a platform to the ceiling or close to the ceiling, a platform screen door that is called a platform fence and opens and closes a waist-height door, and a rope type screen door that opens and closes by raising and lowering a laterally laid rope or bar. All the platform screen doors are the same in that the doors are subjected to open and close control in synchronization with train doors of a train having arrived at a station and stopped at a fixed position. For example, JP-A-2011-213334 discloses the open and close control.
Incidentally, in recent years, development of a wireless train control system has been promoted in which train position detection using a track circuit is replaced with on-board position detection, and communication is wirelessly achieved between the ground side and train side.
Simple achievement of opening and closing the platform screen doors and the train doors in synchronization in this wireless train control system requires a dedicated communication unit for confirming the door open/closed state of both the on-board doors and the ground doors besides the communication unit that notifies the ground of the train position detected by the trains, in order to determine whether the train has stopped at a fixed position or not. Furthermore, there are demands of detecting the train's stopping at the fixed position in real time, and of achieving opening and closing in synchronization with good responsiveness in a short time period.